Measures of central tendency and dispersion

Question 1

measures of central tendency

Answer 1

mean median mode

Question 2

bimodal

Answer 2

two modes

Question 3

multimodal

Answer 3

three or more modes

Question 4

measures of dispersion

Answer 4

range
interquartile range
standard deviation

Question 5

how to calculate IQR

Answer 5

find median (Q2)
find median of minimum and Q2 (Q1)
find median of maximum and Q2 (Q3)
IQR = Q3 - Q1

Question 6

how to calculate standard deviation

Answer 6

calculate (value - mean)^2
calculate the average of this (variance)
calculate square root of this (standard deviation)

Question 7

normal distribution

• relationship between mean, median and mode?
• what measure of central tendency/dispersion to report?

Answer 7

mean = median = mode

mean and SD

Question 8

negatively/left skewed

• appearance
• relationship between mean, median and mode?
• what measure of central tendency/dispersion to report?

Answer 8

outliers to the left/negative; mode to the right
mode > median > mean
report median and IQR

Question 9

positively/right skewed

• appearance
• relationship between mean, median and mode?
• what measure of central tendency/dispersion to report?

Answer 9

outliers to the right/positive, mode to the left
mode < median < mean
report median and IQR

Question 10

when you’re comparing two distributions and atleast one is skewed, what do you report

Answer 10

median and IQR